Aerospace base material production of wrought products and components represented by 0Cr17Ni4Cu4Nb

                                                                    Production process of 0Cr17Ni4Cu4Nb

This steel grade is a singleprocess type of martensitic precipitation hardening stainless steel, which consists of low carbon

content, its corrosion resistance and high wear resistance is better than other general martensitic stainless steel. It also has

good resistance to acid, good machinability and insensibility to hydrogen embrittlement. It has the property of acid resistance

of austenite stainless steel and the hardness of martensitic stainless steel. This steel grade is widely used under 400°C working

environment which requireshigh strength and corrosion resistant parts, such as fighter aircraft,fastener of the missile, engine

parts, turbine blade and walve parts etc..

The main strengthen state of this steel part is bronze state, solid solution state is austenitic structure, when the steel being fast

cooled to room temperature, it forms martensite structure which is supersaturated. Through precipitating rich copper epsilon

phase to improve the strength of the steel during the medium temperature aging.

The structure state depends on the ratio of chemical composition and extremely sensitive. Therefore, the strict control of the

chemical composition is very important.

Niobium is ferrite formation element. The presence of the Niobium causes the appearance of delta ferrite. It easily has crack,

the steel processing temperature range in 1000 ~ 1170°C, the best is not lower than 1000°C

This steel is equal to 17-4PH of AMS5643M, USA.

Melting point: 1404～1440°C; Ms 150°C; Mf 32°C

Specific gravity: Solid solution state 7.78 t/m3; Aging state 7.80/m3

The other steel grade as follows:

2Cr12MoV

X20Cr13

X40Cr13

1Cr12Ni2W1Mo1V

2Cr12NiMo1W1V

1Cr11Co3W3NiMoVNbNB

34CrNiMo6

17Cr2Ni2Mo

X19CrMoNbVn

2Cr11Mo1NiWNb2Cr11Mo1VNbN VN

0Cr17Ni4Cu4Nb